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Products   >   Services   >   End-of-Life Products   >   Prometheus EAL/EL PC/104 SBC
2-in-1 design reduces cost, saves space
ZFx86 processor - 486-DX2, 100MHz
On-board fash file system for DOS
10/100Mbps Ethernet
4 serial, 2 USB, 1 floppy port
IDE and floppy ports
Watchdog timer and real-time clock
IrDA infrared port
Solid-state IDE flashdisk compatibility
Built-in data acquisition with:
16-channel 16-bit A/D
4-channel 12-bit D/A
4-channel 12-bit D/A
24 digital I/O
2 counter/timers
-40 to +85ºC operation
See Prometheus EAL/EL PC/104 SBC Technical Resources
Request Product information
Request Technical Support
Using IDE Devices with Diamond Systems PC/104 CPUs
(.pdf, 17.2 kb)
Prometheus DataSheet
(.pdf, 108.5 kb)
Panel I/O Board Schematic
(.pdf, 153.3 kb)
Analog Interfacing Considerations
(.pdf, 344.7 kb)
Prometheus Example Programs for DSCUD 5.91
(.zip, 1.7 MB)
Universal Driver Software

Prometheus EAL/EL PC/104 SBC

High-Integration PC/104 CPU with Ethernet and Data Acquisition
Now with built-in support for disk emulation in on-board flash!

Prometheus EAL/EL PC/104 SBC
click for a larger image
System Block Diagram
Data Acquisition Circuit
Connection Options
I/O Connectors
Cable-Free Enclosure
Development Kit
Operating System Compatibility
AC Adapter
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Features Benefits
Low-power ZFx86 processor Reduced heat dissipation / no fan required
Integrated Ethernet and system I/O Small size, Light weight
Integrated data acquisition Single-board solution for increased reliability
Guaranteed compatibility
-40/+85ºC operation Compatible with vehicle and outdoor applications
Ruggedization capability Customizable for demanding applications
Increased reliability


The space-saving Prometheus combines a full-featured 486 CPU with an intelligent, professional-quality data acquisition circuit including analog I/O, digital I/O, and counter/timers, all on one board. Its low power consumption of 5 watts eliminates the need for a heat sink or fan and enables guaranteed operation over the range of -40 to +85oC. Prometheus has been successfully used in applications including satellites, military combat vehicles, and process control.

Built-in I/O includes a 10/100Mbps Ethernet port, 2 USB ports, 4 RS-232 ports with serial console capability, PS/2 keyboard/mouse, IDE port, parallel port, and floppy port. Prometheus also includes a real-time clock with backup battery and a programmable watchdog timer with both hardware and software retrigger capability.

Prometheus is compatible with our solid state flashdisk modules that provide IDE-compatible mass storage in a rugged format that bolts onto the board and requires no special drivers. See page 45 for more information. For DOS applications, it includes a built-in flash file system that lets you store DOS operating system and application files right in the on-board flash memory without requiring any external storage. This saves time, reduces cost, and increases the ruggedness of your system. Prometheus is available in three versions:

The built-in data acquisition circuit is identical to the one used on our Athena CPU. It provides 16 analog inputs with 16-bit A/D resolution and a comprehensive set of features, including programmable input ranges, single-ended and differential inputs, and interrupt-based sampling with FIFO support. The circuit also provides 4 12-bit analog outputs with selectable output ranges, 24 digital I/O lines with programmable direction and enhanced output current, and 2 programmable counter/timers for sample rate control, event counting, and programmable interrupt generation.

Prometheus is available in three versions:

Version Description
EA Full-featured model, with 10/100Mbps Ethernet and data acquisition
E Includes Ethernet, no data acquisition
LC No Ethernet or data acquisition; 16MB RAM; Extra-low power consumption of 2 watts

Flexible Storage Options

The on-board 2MB of flash memory contains system BIOS and plenty of room for an embedded OS and user programs in diskless applications. The BIOS provides support for using this flash memory to emulate a diskette drive. It can be configured as either a bootable A: drive or a non-bootable B: drive. Both MS-DOS and ROM-DOS can be loaded, along with application software, right into the flash, totally eliminating the need for external storage media. Click here for more information on this exclusive feature.

For connection to an external hard disk, a 44-pin IDE connector is provided that includes both IDE signals and power. The board will accept the direct mounting of a flash disk module, providing up to 128MB of additional rugged, solid state memory right on the board.

Data Acquisition Circuitry

PROMETHEUS contains a complete data acquisition circuit at a level of performance matching our Diamond-MM-16-AT board (without autocalibration). It has 16 analog inputs with 16-bit resolution and 100,000 samples per second maximum sampling rate. The analog inputs feature programmable gain, unipolar and bipolar input ranges, and single-ended and differential configuration. The 4 analog outputs have 12-bit resolution and output ranges of 0-5V or +/-5V. The 24 digital I/O feature programmable direction. Two counter/timers provide a means for user-generated timing signals, counting of external pulses, and control of the A/D sampling rate.

ATX Power Supply

PROMETHEUS provides ATX power compatibility. The power can be turned on by pressing a momentary switch. If the switch is pressed a second time and held for 2 seconds, the power will turn off. The auxiliary output power connector for external drives is also switched on and off with this circuit.

System Block Diagram

Prometheus Block Diagram

Data Acquisition Circuit

The optional data acquisition circuit on Prometheus is equivalent to a full-featured analog I/O expansion board, with analog I/O, digital I/O, and counter/timer functions.

The 16 analog inputs have 16-bit resolution, programmable gain of 1, 2, 4, and 8, and maximum input range of +/-10V in bipolar mode or 0-10V in unipolar mode. Both single-ended (2-wire) and differential (3-wire) inputs may be accommodated. Using the built-in FIFO and interrupts, the board can achieve sample rates of up to 100KHz in both single-sample and scan modes.

The board also has 4 12-bit analog output channels. The output range is jumper-selected between 0-10V or +/-10V. On power-up, the outputs may be configured to clear to mid-scale or zero-scale, so that they always power up to 0V for safety.

Prometheus also has 24 digital I/O lines organized as 3 8-bit ports. The direction of each port is programmable. When in output mode, each port has a high-drive buffer capable of supplying up to -10/+30mA of output current per pin.

Prometheus has two counter/timers for timing operations. The first counter is 24 bits wide and is generally used to control A/D sampling rate. Driven by a user-programmable 10MHz or 1MHz on-board clock, it can provide output pulses anywhere from 10MHz down to 0.06Hz. The second counter/timer is 16 bits wide and can be driven by either 10MHz or 100KHz on-board clocks or a user-supplied input signal. It can be used for timing, counting/totalizing, or programmable interrupt generator functions.

All data acquisition I/O signals are available on a single 50-pin header that mates with a standard ribbon cable.

Prometheus Data Acquisition Circuit Block Diagram

Connection Options

Prometheus has a total of 9 I/O headers to manage its large quantity of I/O. Because there are several options, including a cable-free method, no cables are provided with the board. All I/O connection options are sold separately.

Panel Board

Our unique panel board provides a convenient, rugged, and cable-free method of accessing all the user I/O on the board, including power. This board plugs directly on the top of the CPU and provides industry-standard connectors for all I/O. All I/O connectors on Prometheus are vertical to accommodate this configuration.

Cable Kit

Key Part No. Description
1 6981012 USB cable
2 C-PRZ-01 Breakout cable
3 C-50-18 50-conductor 18" ribbon cable
4 6981008 Floppy cable
5 6981004 IDE cable
6 C-PRZ-02 Ethernet cable
7 6981005 Auxillary serial port cable
8 6981006 Output power cable
9 6981009 Input power cable

Our cable kit contains a complete set of 9 cables for all I/O connectors. Connectors for all external connections are panel-mountable. Some cables are also available individually.

Some customers design their own cables and harnesses optimized for their particular application. To assist with this effort, all connector pinout and mating connector information is provided in the Prometheus user manual.

You can also mount the CPU as a component on your own baseboard. In this configuration the CPU is flipped over and mounts with the top side facing down onto the baseboard. The vertical I/O connectors on Prometheus accommodate this configuration easily.

I/O Connectors

Special attention was made to provide the ultimate in flexibility and ease of use when integrating the PROMETHEUS CPU into your system. The resulting benefits are lower cost, higher reliability, and shorter assembly time.

System I/O

The 4 serial ports, parallel port, keyboard, mouse, IrDA, speaker, reset, and LED signals are all contained on a single 80- in high-density connector. This connector mates with our I/O panel board to provide cable-free means of accessing all these features with standard connectors. Optionally, you may use a converter cable that provides standard connectors for mounting on a custom I/O panel.


The Ethernet connection is on a dedicated 6-pin header that mates with our I/O panel board or an expansion cable for custom applications.

Data Acquisition

A 50-pin header provides access to all analog I/O, digital I/O, and counter/timer features. This provides an economical means of connecting sensors and controls to the board with an extremely-low-cost standard ribbon cable.


The 2 USB ports are accessed through a dedicated 10-pin header that mates with an industry-standard converter cable. This header also mates with our I/O panel board.

IDE Drive

A compact 44-pin connector provides means of connecting an external hard drive. It also enables connection to a solid-state flash disk module that mounts right on the board, or an optional Flash adapter board that enables you to install an IBM MicroDrive.

Floppy Drive

A standard 34-pin connector provides connection for a floppy drive.

Auxiliary Serial Header

A 6-pin header provides a secondary means of accessing two of the serial ports in cost-sensitive applications requiring only a limited set of I/O.


Input power is provided on a pin header at the bottom of the board. The power contains ATX features of pushbutton on/off capability. An auxiliary 4-pin output header provides power for an external disk drive or other device.

Cable-Free Enclosure

Our cable-free rugged Pandora enclosure system was designed specifically for Prometheus. It is available in multiple sizes to accommodate additional I/O boards and hardware. See page 43 for complete information.

Development Kit

A development kit is available for both the EA and E versions. it includes a Prometheus CPU, VGA board, 256MB flashdisk, Pandora enclosure, cable kit, AC adapter, mounting hardware, and software.

Diamond Systems offers a development kit that includes everything you need to develop your application using the Prometheus CPU. This kit includes the CPU board, a panel I/O board, a complete set of cables for use as an alternative to the panel board, a 3rd party VGA board, a 32MB flashdisk module, a flashdisk programming / expansion board, a 3" Pandora enclosure, a 120VAC wall adapter for power input, mounting hardware, system documentation, and utility software. The kit is available in two versions based on the two available versions of the Prometheus CPU: with and without the data acquisition circuitry.

Get your Linux development project going faster with the Embedded Linux Development Kit. Our Linux Development Kit offers you a pre-built and ready-to-use “Flash Linux” distribution with a file size of only 10MB and a super-low RAM requirement of only 5.5MB. Flash Linux is designed specifically to run on a solid-state flashdisk on Diamond Systems’ Prometheus™ PC/104 CPU board. It enables you to build a completely solid-state Linux-powered embedded computer that boots in just 15 seconds.

Operating System Compatibility

DOS, Linux, QNX, Windows 98


CPU and System
Processor ZFMicro Devices ZFx86
Processor Clock 100MHZ
DRAM Memory EA, E:32MB; LC: 16MB
Flash Memory 2MB
System I/O 4Serial ports, 115 kbps max, 1 parallel port, 2USB ports
Serial protocols RS-232
Serial console Selectable COM1/COM2
Ethernet -E and -EA models only 10/100BaseT 100Mbps max
Desktp Ports PS/2 Keyboard and Mouse
IDE expansion Flash disk module-32-512MB max 44-pin connector for wcternal drives
Watchdog timer Programmable, 0-5 sec
PC/104 Bus Capacity 4 modules
Analog Inputs
Number of inputs 16 single-ended or 8 differential (user selectable)
A/D resolution 16 bits (1/65536 of full scale)
Bipolar ranges ±10V, ±5V, ±2.5V, ±1.25V (software selectable)
Unipolar ranges 0-10V (valid 0-8), 0-5V, 0-2.5V (software selectable)
Temperature Stability 5 ppm/oC
Input bias current 3nA max
Overvoltage protection ±35V on any analog input
Input Impedance 10^13 ohms
Conversion rate 100,000 samples per second with interrupts
Input FIFO 48 samples, Programmable FIFO interrupt depth
Dynamic Stability Less than 1 LSB cross talk at 100KHz
Common Mode Rejection Better than 90db up to 2KHz (less than 1 LSB error)
Analog Outputs
Number of outputs 4 lines, Simultaneous update
D/A resolution 12 bits (1/4096 of full scale)
Output ranges Fixed: ±10V, 0-10V
Programmable possible
Output current ±5mA max per channel
Temperature Stability 5 ppm/oC
Settling time 10µS max to ±1 LSB
Relative accuracy ±1 LSB
Nonlinearity ±1 LSB, monotonic
Reset All channels reset to 0V
Digital I/O
Number of inputs 24 lines, 3.3V and 5.0V compatible
Input voltage
    Logic 0: 0.0V min, 0.8V max
    Logic 1: 2.0V min, 5.5V max
Input current ±10µA max
Input capacitance 10pF max
Output voltage
    Logic 0: 0.0V min, 0.4V max
    Logic 1: 2.4V min, 3.3V max
Output current
    Logic 0: 12mA max per line
    Logic 1: -8mA max per line
A/D Pacer clock 1 24-bit counter/timer for A/D sampling rate control
Clock source 20MHz on-board source or external signal
General purpose 1 16-bit counter/timer
Interrupt trigger End of A/D conversion or scan
Calibration A/D and D/A circuits are pre-calibrated
Power supply PR-Z32-EA-ST: +5VDC +/-5% @ 900mA typical
PR-Z32-E-ST: +5VDC +/-5% @ 600mA typical
PR-Z16-LC-ST: +5VDC +/-5% @ 400mA typical
Operating temperature -40 to +85 °C Extended
Weight 2.8oz/79g

AC Adapter

The AC adapter provides a convenient way to power your embedded CPU during development or demos. it contains the proper connector for direct connection to the CPU board. Each order ships with the correct power cord for the country for the country of destination.

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Prometheus EAL/EL PC/104 SBC
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